[DurocShark]

1983 E350 cutaway (RV) with a carb'd 460ci engine.

It's a Colorado vehicle, now moved to California. I took it for its smog check today, and everything was fine except idle HC's. I'm guessing that it's idle mixture is set for Colorado's elevation, and is now too lean at sea level.

While I could adjust the mixture, I have no way to know if I'm getting in the acceptible range without a gas analyzer. I checked in with the two local shops, and both said they wouldn't take it. "We don't do RVs."

"But it's just a Ford E350!"

"No room."

Sigh.

Any guidance on adjusting it without an analyzer? I only get one free retest, and it's $70 here (cuz it's an RV.) So I don't wanna have to go back more than once.

Reference:

%CO2
Idle: 11.4
2500rpm: 11.4

%O2
Idle: 3.9
2500rpm: 4.9

HC ppm
Idle: 443 Max: 250, Gross Polluter 400
2500rpm: 113 Max: 250, Gross Polluter 400


%CO
Idle: 1.47 Max: 2.20, Gross Polluter 3.70
2500rpm: 0.17 Max: 3.00, Gross Polluter 4.50


Thanks for any help!

Don (hating on carbs at the moment)

[opsuper3]

When was the last time a tune up was done? That is one major cause of high HC. Every other parameter looks good. I had a 1986 f150 that required having the idle screws adjusted to lean it out to pass the test, then fattened back up so I could drive it! I gave up on keeping the f150 licensed, so I went to a fuel injected f350.

Around here are "Emissions Specialists" that will get almost anything through testing for $100. That's where I learned the idle screw trick. If adjust it too far, other parameters will fail. I just marked the idle screws with paint so I could duplicate the setting each year.

[DurocShark]

Tuneup was done 1500 miles ago... Right before we left Colorado.

I just don't have any way to verify I've done it right until I go to the smog place. I wish I did...

[DurocShark]

Ok, I decided to dive in and adjust the carb. Except...



If that image doesn't show, it's a pic of what someone had to do to remove the anti-tamper plugs. They removed the carb and drilled a hole up through the baseplate in order to stick a pick in there to push the plugs out from the inside.

Wha..?

I have the same things, and have succeeded in mangling the opening and shoving one of the plugs in further. CRAP!

What the heck were they thinking??!?! How can the silly thing be adjusted without pulling the whole carb?

I'm so frustrated right now I can't see straight.

[DurocShark]

Seriously, if there's someone local to Anaheim, CA who would come and make the @$%^ thing pass smog, I'd pay. The temp tags from CO expire today, and AAA didn't give me anything to extend that even though I already paid all the fees.

[Kruser]

Originally Posted by DurocShark

What the heck were they thinking??!?! How can the silly thing be adjusted without pulling the whole carb?

That's how it has to be done. I've done many of carb kits where you CAREFULLY had to knock out those plugs. Perhaps it should be worded "What was our government thinking?" because the car manufacturers were prodded by the EPA to stop people from tampering with them.
Don't be frustrated. You can use a Dremel tool to cut a slot out of the base plate to access the adjustment screw. The area between the current hole and the outside of the base plate can be butchered and it won't affect the base plate gasket's sealing ability. BTW, some carbs made you buy a high dollar tool because they had funky screw heads on the adjustment screws. (Or, you file a slot in the screw head so a large jewelry screwdriver would work )

[819fva]

400 gross polluter is that your max or the 250

[819fva]

I had the same thing on my car. I found out certain ways of doing it. I'm sure CA is pretty similar to AZ for smog tests. Here in AZ the car is put on rollers dyno and series of test performed. I will list the things needed to be done.
1. Make sure your rear bakes work good (it going to need to stop on the rollers)
2. crank your idle to about 1800 rpm
3. depending what time of the month there is going to be a line to get tested this is key( keep that engine hot )
What it shows me is that there is unburned fuel being pushed out of the exhaust so you want the manifolds hot,hot,hot. These cost nothing.

Try seafoam motor tune through the intake. High powered ignition system which my increase mpg

[Canuck623]

That reading is bad at idle but ok at higher speeds. I would suspect your power valve is leaking. That looks to be a Motorcraft 2150 carb. The power valve should be in the bottom of the fuel bowl area. If you have the carb off anyway put one in. They will boot you out of the test lanes if your idle is too high so don't try that. A couple 100 RPM will be ok. Put about 8 to 10 OZ of Methyl Hydrate in the tank. Once you have the power valve replaced and the carb back on turn the mixture screws in till the engine begins to stumble then back them out just enough that the engine idles without stalling. Bump the timing a couple of degrees add a bit of RPM and go pass the test.

[opsuper3]

I was hoping that you had resolved this.

Anyhow, you can drill the caps and use a self tapping screw to pull it out. If the cap rotates, you can use a mini pick to pull it out.

[DurocShark]

No, not resolved. I wish.

I tried to drill into the plugs. They're hardened steel, and I dulled a couple of bits before giving up. I also jammed one of the plugs in further (pushing too hard on the drill out of frustration).

I'm ordering a rebuild kit (and a power valve since they're only $25.. I doubt it's the cause but it's cheap insurance) and gonna pull it off and do this properly.

Have to wait until after the new year now. Too much family crap going on.

[Kruser]

Originally Posted by DurocShark

I tried to drill into the plugs. They're hardened steel, and I dulled a couple of bits before giving up. I also jammed one of the plugs in further (pushing too hard on the drill out of frustration).

Take your carb apart as much as you can. Put a tapered center punch into a vice, with the punch pointing straight up and tighten it in the vice. Take the base plate of your carb and have your punch holding the base plate by putting one of the four hold-down holes over the punch. The punch is now holding your carb's base plate and you can use both hands to do work on the carb. (You could buy an expensive tool to hold the base of your carb, but few people work on carbs for a living anymore)
You can now drill into the bottom side of the carb just like somebody has done in the photo. USE EXTREME CAUTION DOING THIS, as it would be possible to drill into the idle jet adjustment screw. The plug will be hardened metal, but the base plate of your carb is soft aluminum. Drill several holes to remove enough metal so that the next tool to use is a Dremmel with a small paper-thin cut off wheel. This will help remove enough metal surrounding the plug so that it slides out. After the plugs come out, you can remove the idle screws and give everything a thorough cleaning and install a new carb kit, including a new power valve as mentioned in a previous post.
The first time you perform this, you will be nervous and scared. After the first one, you will be comfortable doing it again.

[Canuck623]

Cheap carb holder is two tapered punches that the taper is wider than the holes in the carb. Clamp them in a vise and then put the carb over them. Voila!! Carb is held right where you put it.

[DurocShark]

Wow. And to think I've always just used a chunk of wood with a hole cut out about the size of the barrels to do carb work. What's all this fancy stuff ya'll are talking about?



I've rebuilt carbs before. My challenge is always adjusting them, I usually just take the car to a shop for the adjustments. Especially 4bbl carbs. I'm going to try using the max vacuum technique this time and see.

[Kruser]

Originally Posted by DurocShark

I've rebuilt carbs before. My challenge is always adjusting them, I usually just take the car to a shop for the adjustments.

Depending on the state you live in, BY LAW, you may have to use fancy/schmancy exhaust sniffers to adjust your carb. Using a vacuum gauge and a tach is the easiest and best way to do it, however.

[DurocShark]

Hmm... I'm in Cali. I wouldn't be surprised that's the case.

But neither the DMV nor the mechanic mentioned that. So I don't know anything...

[DurocShark]

Originally Posted by 819fva

400 gross polluter is that your max or the 250

Sorry, didn't see this.

250 is the max to pass. Over 400 means you get flagged for annual checks as well as having to go to "test only" places. At least, that's what it used to mean.

[819fva]

Did you change the accelerator pump on the carb? Maybe a new factory carb or a someone to rebuild it? That is a lot of fuel unburned going out the tailpipe.

[DurocShark]

The rebuild kit will have one, won't it?

[Canuck623]

Yes it should have that and a new power valve as well.